Method of writing contents in memory during a power up sequence using a dynamic redundancy register in a memory device

• US 10,360,964 B2
• Filed: 12/27/2017
• Issued: 07/23/2019
• Est. Priority Date: 09/27/2016
• Status: Active Grant

• Current Assignee: Integrated Silicon Solution Incorporated (Uphill Investment Co.)
• Original Assignee: Spin Memory, Inc.
• Inventors: Berger, Neal, Louie, Benjamin, El-Baraji, Mourad, Crudele, Lester, Hillman, Daniel
• Primary Examiner(s): Byrne, Harry W
• Assistant Examiner(s): Begum, Sultana
• Application Number:
  US15/855,589
• Publication Number:
  US 20180122447A1
• Time in Patent Office: 573 Days
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 2212/222 Non-volatile memory
• CPC Class Codes: G11C 11/1653 Address circuits or decoders
• CPC Class Codes: G11C 11/1673 Reading or sensing circuits or methods
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: G11C 11/1677 Verifying circuits or methods
• CPC Class Codes: G11C 11/1697 Power supply circuits
• CPC Class Codes: G11C 13/0033 Disturbance prevention or evaluation; Refreshing of disturbed memory data
• CPC Class Codes: G11C 14/0081 and the nonvolatile element is a magnetic RAM [MRAM] element or ferromagnetic cell
• CPC Class Codes: G11C 7/1039 using pipelining techniques, i.e. using latches between functional memory parts, e.g. row/column decoders, I/O buffers, sense amplifiers
• CPC Class Codes: G11C 7/20 Memory cell initialisation circuits, e.g. when powering up or down, memory clear, latent image memory

Abstract

A method of writing data into a memory device is disclosed. The method comprises utilizing a pipeline to process write operations of a first plurality of data words addressed to a memory bank. The method further comprises writing a second plurality of data words and associated memory addresses into a cache memory, and wherein each data word of the second plurality of data words is associated with a pending operation. Additionally, the method comprises detecting a power up signal and responsive to the power up signal, transferring the second plurality of data words and associated memory addresses from the secure memory storage area to the cache memory. Finally, responsive to the transferring, and before the memory device is powered up, the method comprises processing the second plurality of data words and associated memory addresses from the cache memory to the pipeline for writing data to the memory bank during power up.

Claims

1. A method of writing data into a memory device, the method comprising:

utilizing a pipeline to process write operations of a first plurality of data words addressed to a memory bank;

writing a second plurality of data words and associated memory addresses into a cache memory, wherein said cache memory is associated with said memory bank and wherein further each data word of said second plurality of data words is either awaiting write verification associated with said memory bank or is to be re-written into said memory bank;

detecting a power down signal;

responsive to the power down signal, transferring the second plurality of data words and associated memory addresses from said cache memory into a secure memory storage area in the memory bank;

detecting a power up signal;

responsive to the power up signal, and before said memory device is powered up, transferring the second plurality of data words and associated memory addresses from said secure memory storage area to said cache memory; and

responsive to the transferring, and before said memory device is powered up, processing the second plurality of data words and associated memory addresses from said cache memory to said pipeline for writing data to the memory bank during power up.

2. A method as described in claim 1 wherein said memory bank comprises a plurality of spin-transfer torque magnetic random access memory (STT-MRAM) cells.

3. A method as described in claim 1 further comprising:

responsive to said power down signal, transferring any partially completed write operations of said pipeline to said secure memory storage area.

4. A method as described in claim 1 further comprising:

responsive to said power down signal, copying any partially completed write operations of said pipeline to said cache memory.

5. A method as described in claim 1 wherein said transferring comprise utilizing a secure communication process substantially compliant with one of:

voting;

ECC encoding;

use of multiple copies;

comparing multiple copies; and

voting from multiple copies.

6. A method as described in claim 1 wherein said power down signal originates from a system level software stack and represents a system wide orderly power down event.

7. A method as described in claim 1 further comprising removing a data word and its associated address from said cache memory responsive to an indication that said data word has been verified as properly written to said memory bank.

8. A method of writing data into a memory device, the method comprising:

utilizing a pipeline to process write operations of a first plurality of data words addressed to a memory bank;

writing a second plurality of data words and associated memory addresses into a cache memory, wherein said cache memory is associated with said memory bank and wherein further each data word of said second plurality of data words is either awaiting write verification associated with said memory bank or is to be re-written into said memory bank;

detecting a power down signal;

responsive to the power down signal, transferring the second plurality of data words and associated memory addresses from said cache memory into a secure memory storage area in the memory bank;

detecting a power up signal; and

responsive to the power up signal, and before said memory device is powered up, transferring the second plurality of data words and associated memory addresses from said secure memory storage area to said pipeline for writing data to the memory bank during power up.

9. A method as described in claim 8 wherein said memory bank comprises a plurality of spin-transfer torque magnetic random access memory (STT-MRAM) cells.

10. A method as described in claim 8 further comprising:

responsive to said power down signal, transferring any partially completed write operations of said pipeline to said secure memory storage area.

11. A method as described in claim 8 further comprising:

responsive to said power down signal, copying any partially completed write operations of said pipeline to said cache memory.

12. A method as described in claim 8 wherein said transferring comprise utilizing a secure communication process substantially compliant with one of:

voting;

ECC encoding;

use of multiple copies;

comparing multiple copies; and

voting from multiple copies.

13. A method as described in claim 8 wherein said power down signal originates from a system level software stack and represents a system wide orderly power down event.

14. A method as described in claim 8 further comprising removing a data word and its associated address from said cache memory responsive to an indication that said data word has been verified as properly written to said memory bank.

15. A memory device for storing data, the memory device comprising:

a memory bank comprising a plurality of addressable memory cells;

a pipeline configured to process write operations of a first plurality of data words addressed to said memory bank;

a cache memory operable for storing a second plurality of data words and associated memory addresses, wherein said cache memory is associated with said memory bank and wherein further each data word of said second plurality of data words is either awaiting write verification associated with said memory bank or is to be re-written into said memory bank; and

a logic module operable to;

detect a power down signal;

responsive to the power down signal, transfer the second plurality of data words and associated memory addresses from said cache memory into a secure memory storage area reserved in the memory bank;

detect a power up signal;

responsive to said power up signal, and before said memory device is powered up, transfer data words and associated memory addresses from said secure memory storage area to said cache memory; and

before said memory device is powered up, process said data words and associated memory addresses from said cache memory to said pipeline for storage to said memory bank during power up.

16. A memory device as described in claim 15 wherein said plurality of addressable memory cells of said memory bank comprises spin-transfer torque magnetic random access memory (STT-MRAM) cells.

17. A memory device as described in claim 15 wherein said logic module utilizes a secure communication process substantially compliant with one of:

voting;

ECC encoding;

use of multiple copies;

comparing multiple copies; and

voting from multiple copies.

18. A memory device as described in claim 15 wherein a data word and its associated address are removed from said cache memory responsive to an indication that said data word has been verified as properly written to said memory bank.

19. A memory device for storing data, the memory device comprising:

a memory bank comprising a plurality of addressable memory cells;

a pipeline configured to process write operations of a first plurality of data words addressed to said memory bank;

a cache memory operable for storing a second plurality of data words and associated memory addresses, wherein said cache memory is associated with said memory bank and wherein further each data word of said second plurality of data words is either awaiting write verification associated with said memory bank or is to be re-written into said memory bank; and

a logic module operable to;

detect a power down signal;

responsive to the power down signal, transfer the second plurality of data words and associated memory addresses from said cache memory into a secure memory storage area reserved in the memory bank;

detect a power up signal; and

responsive to said power up signal, and before said memory device is powered up, transfer data words and associated memory addresses from said secure memory storage area to said pipeline for storage to said memory bank during power up.

20. A memory device as described in claim 19 wherein said plurality of addressable memory cells of said memory bank comprises spin-transfer torque magnetic random access memory (STT-MRAM) cells.